Growth-inhibiting effects of Paeonia lactiflora root steam distillate constituents and structurally related compounds on human intestinal bacteria

Abstract

The growth-inhibiting activities of Paeonia lactiflora (Paeoniaceae) root steam distillate constituents and structurally related compounds against nine harmful intestinal bacteria and eight lactic acid-producing bacteria were compared with those of two antibiotics, amoxicillin and tetracycline. Thymol, α-terpinolene, (-)-perilla alcohol and (1R)-(-)-myrtenol exhibited high to extremely high levels of growth inhibition of all the harmful bacteria, whereas thymol and α-terpinolene (except for Lactobacillus casei ATCC 393) inhibited the growth of all the beneficial bacteria (MIC, both 0.08-0.62 mg mL(-1)). Tetracycline and amoxicillin exhibited extremely high level of growth inhibition of all the test bacteria (MIC, <0.00002-0.001 mg mL(-1)). 1,8-Cineole, geraniol, (-)-borneol, (1S,2S,5S)-(-)-myrtanol, nerol, (S)-(-)-β-citronellol and (±)-lavandulol also exhibited inhibitory activity but with differing specificity and levels of activity. Structure-activity relationship indicates that structural characteristics, such as geometric isomerism, degrees of saturation, types of functional groups and types of carbon skeleton, appear to play a role in determining the growth-inhibiting activity of monoterpenoids. Global efforts to reduce the level of antibiotics justify further studies on naturally occurring P. lactiflora root-derived materials as potential preventive agents against various diseases caused by harmful intestinal bacteria such as clostridia.

The ecological role of volatile mediated interactions belowground

“…Here, VOCs of F. culmorum did not significantly stimulated bacterial motility and function as repellence as in the case of Burkholderia or Janthinobacterium. In accordance to previously reported antibacterial activity of fungal VOCs (Ngan et al 2012;Keri et al 2015;Schmidt et al 2016), the compounds benzothiazole or terpenes including 1,8-cineole and camphene emitted by F. culmorum in soil might played a role in the inhibition of bacterial motility and growth.…”

Growth-inhibiting effects and chemical composition of essential oils extracted from Platycladus orientalis leaves and stems toward human intestinal bacteria

“…Although the mode of action of essential oils and their terpenes on bacteria is not thoroughly understood, it has been suggested that they are involved in such mechanisms as coagulation of cell contents, disruption of the proton motive force, and cytoplasmic membrane (21,22). We demonstrated the growth-inhibiting effects of cedrene derived from the essential oil of P. orientalis leaves against C. perfringens and E. coli.…”

“…microorganisms and have been suggested as alternatives to the used antibiotics (7,21). Although the mode of action of essential oils and their terpenes on bacteria is not thoroughly understood, it has been suggested that they are involved in such mechanisms as coagulation of cell contents, disruption of the proton motive force, and cytoplasmic membrane (21,22).…”

Anti-biofilm Activities and Chemical Composition of Essential Oil from Burdock Leaf

“…Previous studies reported that compounds such as β-eudesmol (Costa et al, 2008;Kumar et al, 2011), borneol (Ngan et al, 2012;Al-Farhan et al, 2010;Elaissi et al, 2011), 1-octen-3-ol (Kim et al, 2004;Yu et al, 2004), linalool (Ngan et al, 2012;Alviano et al, 2005;Singh et al, 2008), benzyl alcohol , phenylethyl alcohol , α-eudesmol (Costa et al, 2008;Wang et al, 2005) exhibited significant antibacterial activities. The high antimicrobial activity of the essential oil of burdock leaf against streptococcus pneumoniae, S. aureus, S. dysenteriae, E. coli and S. typhimurium was probably due to the combined action of β-eudesmo, borneol, 1-octen-3-ol, linalool, benzyl alcohol, phenylethyl alcohol and α-eudesmol present in burdock leaf essential oil.…”